M.S.

Montréal Trigonix inc. 2018

The purpose of this investigation was to study three classes of sequencing rules in a simulated Job Shop. A computer program simulating the Job Shop was developed to provide an experimental base from which the behavior of the Shop could be observed. In the simulated Job Shop, three sequencing rules, one from each class, were tested. The sequencing rules used were First Come First Serve (FCFS), Shortest Processing Time (SPT), and Probability Sequencing (PS). Due date performance, number of jobs processed in a simulated interval, number of jobs late, mean lateness and in-process inventory level were the measures of performance used. The results indicated that at low traffic density there was no appreciable difference among the measures of performance for the three sequencing rules. At high traffic density SPT had the lowest inventory level but its mean lateness was larger than That of FCFS even Though its number of jobs late was smaller. The performance of FCFS and SPT did not change with changes in allowed flow time but for PS the in-process inventory level increased with decreasing allowed flow time and The number of jobs processed decreased with decreasing allowed flow time. / Master of Science

A review of the existing, more prominent velocity profile models for two and three-dimensional incompressible flows was presented, with emphasis placed on those that had previously shown their ability to correlate experimental data taken under various conditions. This review included velocity profile models that seemingly could represent flows in which the cross flow velocity vector reverses direction. The various methods of determining a wall shearing stress by semi-empirical considerations for two and three-dimensional flows was discussed. A direct measurement of the wall shearing stress in a three-dimensional flow field was used to infer the most accurate method of applying two-dimensional techniques to three-dimensional conditions in order to obtain reasonable values for the friction losses in a boundary layer. A discussion of the error in the determination of the skin friction coefficient by use of the Glauser Chart was presented. The experimental constants in the law of the wall formulation are shown to be the basis for an error which may be in excess of 15 per cent in the determination of the skin friction coefficient. Finally, a thorough comparison of the previously reviewed two and three-dimensional velocity profile models was made with some of the most complete sets of experimental data available to date. / Master of Science

During the design of an aircraft it becomes necessary to predict the aircraft handling qualities. Previously, this has been done through the use of pilot opinion ratings of similar vehicles. However, it is desirable to develop more objective means of predicting handling qualities which also do not require the expensive flight testing or simulation necessary to obtain pilot ratings directly. An analysis of the closed-loop pilot-airframe system is performed, utilizing the linear human-pilot transfer function in conjunction with conventional servoanalysis techniques. Boundaries are developed on aircraft frequency and damping ratio for "good" longitudinal short-period control. The lateral phugoid mode is also investigated and the conclusion reached is that this mode cannot be controlled in a manner resulting in "good" pilot ratings. Comparison of the results obtained for the longitudinal short-period mode with experimental data indicates that the analysis is valid. Experimental data is lacking for comparison in the case of the lateral phugoid mode. / M.S.

When some population values are completely from observation, the distribution from which the observations came is said to be truncated. Estimation of the parameters from truncated distributions has been an open field for research. This thesis examines the developments which have taken place in this area, giving the major writers and the methods used by them to obtain estimators. A. C. Cohen is responsible for much work involving the maximum likelihood procedure. Using the method of moments and several methods which they have developed, Rider, Plackett, Samford, Moore, Des Raj, and Halperin have made significant contributions. The Poisson, Normal, Binomial, Negative Binomial, and Gamma distributions are included in the investigation and along with the estimators, in some cases, asymptotic variances are given. Though much work has been done, there are many things left to be investigated. Only a small number of distributions have been dealt with, with all multivariate distributions other than the normal lacking any investigation. It is not known how the estimators are affected by small sample sizes, and with the aid of the computer variances can be examined. A new problem arises when the points of truncation are not clearly defined and complicated equations often make estimators difficult to fine. / M.S.

The purpose of this study was to explore a method for developing production standards for a low-production fourdrinier paper machine producing a wide range of specialty paper types. The approach was based primarily on noted historical deviations of actual production from production indicated from the use of formulas or nomographs describing the theoretical production possible. Using FORTRAN IV on an IBM 360, a program capable of accepting and analyzing historical data in order to develop production standards was developed. The program is also capable of comparing production runs on a particular day with the historical standards. A similar approach could be applied in both specialty mills and in high-production mills using the fourdrinier paper machine. The production standards developed from such a method would provide a basis for standard cost accounting by product and by production run, would permit evaluation of changes in the machine, and would provide a means to evaluate machine and crew performances. Quality control chart methods incorporated in the computer program would also aid in pointing out production runs with extreme deviations from the historical standards of production in order that checks could be made for assignable causes. / M.S.

M. S.

M.S.

A procedure was developed for the quantitative separation of major fermentation products of uniformly labeled glucose-C¹⁴ produced by bovine rumen microorganisms in vitro. After 45 min, the fermentation mixture was fractionated into (a) one control subsample, and duplicate fractions of (b) solid matter “precipitate“, (c) ether extract, (d) “amino acid“, (e) “sugar“, (f) CO₂, and (g) CH₄. Similar fractionation of an unfermented control sample was made. A portion of the fermentation ether extract was subjected to column chromatography to resolve (a) C₁, (b) C₂, (c) C₃, (d) C₄, and (e) C₅ fatty acids, (f) succinic, and (g) lactic acids. Each fraction was analyzed in triplicate for C¹⁴ by a direct plating technique. Corrections for geometry, self absorption, and efficiency were made by direct plating additional triplicate fraction subsamples, each containing a uniformly labeled glucose-C¹⁴ internal standard. The data were expressed as per cent recovery of added C1u. The results indicated that glucose was rapidly fermented with most of the C¹⁴ found in the ether extractable fraction as acetic acid. Significant levels of C¹⁴ were found in the “precipitate“ fractions. The data were compatible with evidence that CH₄ was derived from CO₂. The results of 6 trials indicated that there was no significant difference in the distribution of products resulting from the in vitro fermentation of uniformly labeled glucose-C¹⁴ between animals, between days within animals, or between times within days. / Ph. D.